1. Field of the Invention.
The present invention relates to piezoelectric motors and particularly to such a motor that is particularly well suited for use in the appliance timer industry.
2. Description of the Prior Art.
Motors that are used for powering timers in appliances are well known in the art. Such motors should be relatively small, displacing volumes of about five to ten cubic inches or less, but at the same time capable of turning mechanical timing cams and switches precisely and reliably. Many such conventional motors have been developed, all of which require a relatively large number of parts, such as a permanent magnet rotor, a metal stator, a coil winding, and a field plate, which parts can be relatively expensive to fabricate. Many piezoelectric motors have been developed for use in such products as watches, cameras and even a small fan. See for example, the article entitled "Piezoelectricity Powers Tiny Fans", by David S. Bak in Design News, Oct. 24, 1983 pp. 86-87. While all of these piezoelectric motors are small, none are of a design that would be useful for appliance timing functions.